Double needle row warp knitting machine and method of operating the same

ABSTRACT

Method of operating a double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, at least one of the guide bars forming stitches on both of the needle bars, includes the step of displacing the guide bars in a single oscillating movement over the needle bars for one rotation of the main drive shaft. The machine includes transmission means driven by the main drive shaft and having a 1:1 transmission ratio for swinging the guide bars in accordance with the foregoing method.

HJHliiQ Lul States Patent 1191 Apken et al. 1 Oct. 22, 1974 [54] DOUBLE NEEDLE ROW WARP KNITTING 3.460.358 8/1969 Kohl (16/87 MACHINE AND METHOD OF OPERATING 149L558 1/1970 Kohl (16/87 3590.600 7/1971 Kohl (16/87 THE SAME [75] Inventors: Rainer Apken, Rhcydt; Egon Fritz,

Monchcngladbach, both of Germany 73 Assignee: w. Schlat'l'mrst & 00.,

Monchengladbach, Germany [22] Filed: July 10, 1972 [21] Appl. No.: 270,027

[30] Foreign Application Priority Data July 9, 1971 Germany 2134279 [52] US. Cl. 66/87 [51 Int. Cl D04b 23/02 [58] Field of Search 66/87 [56] ReferencesCited UNITED STATES PATENTS 3,221.520 12/1965 Bassist 66/87 I a 0 2o 40 50 a0 00 m M; 120 1194 249220210 220 z'aaiaaz'min 32/370 Primary ExaminerRonald Feldbaum Attorney, Agent, or FirmHerbcrt L. Lcrncr [57] ABSTRACT Method of operating a double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, at least one of the guide bars forming stitches on both of the needle bars, includes the step of displacing the guide bars in a single oscillating movement over the needle bars for one rotation of the main drive shaft. The machine includes transmission means driven by the main 12 Claims, 18 Drawing Figures mimaawzz m 3.842.625 MR1 4 ME/ I 4 B HUIU FMENIEB Z 3.8&2.625

DOUBLE NEEDLE ROW WARP KNITTING MACHINE AND METHOD OF OPERATING THE SAME The invention relates to double needle-bar warp knitting machine and, more particularly, to such a machine having a plurality of guide bars, such as a Raschel knitting machine, particularly, provided with a control system for moving the guide bars so that at least one guide bar forms stitches on both needle bars, as well as a method of operating such a machine.

If a double needle-bar warp knitting machine having a plurality of guide bars, such as a Raschel knitting machine, especially, is to be operated so that at least one of the guide bars forms stitches on both needle bars, in the heretofore known warp knitting machines of this general type, control of the guide bars is effected so that initially the guide bars are disposed symmetrically to the elevational or vertical axis (axis of symmetry) of the machine, and both rows of latch needles or the like are in knocking-over or cast-off position. From this intermediate position, an evading movement is carried out initially so that the latch needles, which are to be brought into lapping position, are no longer located beneath the guide bar packet. This lapping position is necessary to produce underlapping. Then, overlapping is produced, wherein the eye needles of the guide bars are swung through the latch needle bars so that they are located forward of the needle latches or tongues. Thereafter, the eye needles must be swung back quickly so that the threads of the stitch-forming guide bars come under the needle latches. The latch needle begins to drop, at the same time.

After the latch needle has been knocked over or cast off, an evading movement begins once again in order to bring the eye needles for the second latch needle bar, which is now becoming active, into the correct underlapping position. The result thereof is that with the heretofore known warp knitting machines of this general type, a swinging movement or oscillation of the guide bars corresponds substantially to an angle of rotation of 120 of the main drive shaft of the machine or, in other words, during one rotation of the main drive shaft of the machine, the guide bars carry out three swinging or oscillating movements or have three times the fundamental frequency of the rotary speed of the main drive shaft. Since the guide bars have three times the frequency of that of the main shaft rotary speed, the machine is able to operate only at a relatively low rotary speed.

It is accordingly an object of the invention of the instant application to provide method and means for operating a double needle-bar warp knitting machine wherein the rotary speed of the machine is markedly increased over that of heretofore known machines of this general type.

With the foregoing and other objects in'view there is provided in accordance with the invention, in a method of operating a double needlebar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, at least one of the guide bars forming stitches on both of the needle bars, the step of displacing the guide bars in a single oscillating movement over the needle bars for one rotation of the drive shaft, the guide bars being thus oscillated at the same frequency as that of the rotation of the main drive shaft of the machine.

A slight delay or pause in the oscillating movement of the guide bars is permissible as long as the increase in'the operating speed of the machine, which is sought after by the invention, is not thereby adversely affected to any serious extent. In accordance with another feature of the invention, the greatest possible machine operating speed is attained when the oscillating movement of the guide bars is sinusoidal. A sinusoidal oscillating movement of the guide bars has the advantage, besides that of a uniform course of movement and consequent smoothly running operation of the machine, of permitting considerable simplification of the drive system for the guide bar oscillation.

In accordance with an especially advantageous further feature of the method of the invention, there is provided a shorter pause in the movement of the knitting meedles of both needle bars in the knocking-over position thereof than in the lapping position therof. In accordance with a more specific feature of the invention, there is provided a pause in the knitting needle movement in the knocking-over position thereof which is as short as possible but not longer than a pause correspondirig to a rotary angle of of the main drive shaft of the machine. Independently thereof or even in addition thereto, and in accordance with yet another feature of the invention, the pause in the lapping position corresponds to an angle of rotation of the main drive shaft of substantially 180, and preferably an angle of rotation of from to 220.

In accordance with an added feature of the method of the invention, we produce an overlap on the knitting needles of the one needle bar by the guide bar associated therewith, and simultaneously an underlap on the knitting needles of the other, needle bar by the guide bar associated therewith. In accordance with a consequent feature of the invention, I back-fill with the needles forming the underlap within the knitting needle bar. To increase the reliability when drawing off the warp knitting cloth, it is advantageous, in accordance with the invention, not to draw off the knitted cloth, continuously but rather discontinuously or intermittently so that the drawing-off is effected at least chiefly in the knocking-over position of the knitting needles.

To carry out the method of the invention, a double needle-bar warp knitting machine, especially a Raschel knitting machine, having a main drive shaft and a plurality of guide bars operatively connected thereto is provided, according to the invention,'with means for controlling the movement of the guide bars so that at least one guide bar forms stitches on both needle bars, and transmission means driven by the main machine drive shaft to 'effect the oscillation of the guide bar, the transmission'means having a transmission ratio of 1:1. In this way, an objective of the invention is attained that the guide bars execute only one oscillation in the course of one rotation of the main machine drive shaft.

In accordance with another feature. of the invention, the transmission means for effecting the swinging or oscillating movement of the guide bars comprises an eccentric drivingly connected to the main drive shaft of the machine, the purely sinusoidal oscillating movement of the guide bars effected thereby thus affording especially smooth and rapid running of the machine.

To be able to produce an overlap on the knitting needles of the one needle bar and, simultaneously, an underlap on the knitting needles of the other needle bar,

in accordance with a further feature of the invention, the needles of the guide bars are spaced from one an other a distance great enough to permit the knitting needles to penetrate into the space therebetween.

In order to avoid increasing the spacing between the guide bar or eye needles far too much, however, and yet provide adequate space for as many guide bars as possible, in accordance with an added feature of the invention, one or more guide bar needles are disposed at an angle of substantially 90 to the other guide bar needles of the respective set.

When the separation between the guide bar needles is relatively narrow, it is advantageous not to cast into the knitting needle bar every possible needle that can be fitted therein but rather, selectively, after each needle cast into the needle bar, to leave two locations vacant at which needles could have been cast into the bar, so that the guide bar needles can then oscillate, even broadside, through the relatively wide passages that are thus provided. According to yet another feature of the invention, in producing many a knitted fabric, the knitting needles of both needle bars are offset with respect to one another.

Although the invention is illustrated and described herein as embodied in double needle-bar warp knitting machine and method of operating the same, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. la is a chart of displacement-time curves of knitting needle strokes per rotary angle a of the main drive shaft of a double needle bar warp knitting machine having a plurality of guide bars, as known in the prior art; and

FIGS. 1b to If are diagrammatic fragmentary views of the prior art machine showing different stages of the interaction of the needles thereof;

FIG. 2a is a chart similar to that of FIG. 1a as applied to the machine of the instant application and the method of operating the machine;

FIGS. 2b and 2c are diagrammatic, fragmentary horizontal sectional views of the machine of the invention at the level of both needle bars, taken at different stages of the operation thereof;

FIGS. 2d and 2i are fragmentary views somewhat similar to FIGS. 1b to If of the machine of the invention;

FIGS. 3a and 3b are enlarged elevational views, mutually rotated through an angle of 90 about the vertical axis thereof, of an individual guide bar needle which is twisted through an angle of 90; and

FIG. 4 is a diagrammatic view of a double needle-bar warp knitting machine according to the invention, showing the essential parts thereof.

Referring now to the drawings and first, particularly, to FIG. la thereof, there is shown therein a diagram of the respective stroke H of the knitting needles plotted against the rotary angle and of the main drive shaft of an exemplary prior art machine of the general type as that of the invention. Curve I represents the movement of the knitting needles in the needle bar I, while curve 2 represents the movement of the knitting needles in the needle bar II. The oscillating movement of the guide bars is represented by the curve 3.

If one considers the position a 30 of the machine main drive shaft as the starting point, bothknitting needles are knocked over in that position, and the guide bars are disposed symmetrically to the vertical axis i..e., the symmetry line of the machine. This position is shown schematically in F IG. 1b wherein the needle bars I and II carrying latch or tongue needles 11 and 12 are clearly seen to be in knocked-over or cast-off position. Eye needles 13 of guide bars not shown in FIG. 1b are disposed symmetrically to the vertical axis 5 of the machine.

From this mid-position, an evading movement first takes place toward the left-hand side of FIG. lb so that the latch needles 12 which are to be brought into lapping position, are no longer located beneath the packet of guide bars. This position is necessary for the purpose of forming the underlap, and is represented in FIG. 10 and correspond to a rotary angle a of the machine main drive shaft. The latch needles 12 have thereby begun to rise. Thereafter the eye needles 13 swing through the latch needles'l2 so that they are then located forward i.e., to the right-hand side, as viewed in FIG. 1d, of the hooks of the needles 12 at a rotary angle of the machine main shaft of about After the upward displacement of the latch needles 12 has been completed, the guide bars and the eye needles 13 associated therewith swing back so that the threads come beneath the hooks of the needles 12. FIG. le shows the position corresponding to a rotary angle a of about of the main drive shaft of the machine at which the latch needles 12 are beginning to drop.

After the knocking-over or casting-off of the latch needles 12, an evading movement begins again in order to bring the eye needles 13 into the correct position for forming the underlap with the latch needles ll of the needle bar I which now come into action. At a rotary angle a 210 of the machine main shaft, as shown in FIG. 1f, the same position as in FIG. 1b is again attained, however, the evading movement then takes place toward the right-hand side as shown in FIG. 1fi.e. the aforedescribed performance is repeated with the latch needles ll of the bar I but in the opposite-direction.

It is very readily apparent that with the heretofore known method and machine, according to the illustrations pertaining thereto in FIGS. 10 to If, the guide bars carry out three oscillations during a complete rotation of the main drive shaft of the machine which correspondsto a rotary angle a 360, each of the oscillations corresponding, in turn, to a rotary angle a 120 of the main machine shaft. In contrast thereto, as will be described hereinafter with respect to FIGS. 2a to 2i, the method of the invention is distinguished by the fact that the guide bars carry out only one oscillatory movement during a single rotation of the main drive shaft of the machine. In FIGS. 2a to 2i, the method of the invention is disclosed with respect to a purely sinusoidal oscillatory movement of the guide bars. FIG. 2a again shows the stroke H of the latch needles dependent upon the rotary angle a of the main drive shaft of the machine. The stroke curve 6 of the latch needles 11 of the forward bar I, and the stroke curve 7 of the latch needles 12 of the rear bar 11 are clearly shown in FIG. 2a. Whereas in the heretofore known method according to FIG. 10, for example in the position corresponding to the rotary angle a 30 of the main machine drive shaft, the latch needles are both simultaneously in knocking-over position, there is no such position in the method of the invention of the instant application. With the preferred method of the invention shown in the drawing, both of the latch needles are in lapping position wherein, for example, the machine main shaft is in the angular position a= 80 and a= 260. The sinusoidal oscillatory movement of the guide bars is represented by the dot-dash curve line 8 in FIG. 2a. The turning points thereof are at a 150 and at a 280.

For a better understanding of the disclosed embodiment of the invention, a horizontal section through the machine at the level of both needle bars I and II is shown in FIGS. 2b and 2c and, in fact, at the instant in which the main shaft of the machine has attained an angular position of a 100 (FIG. 2b) and a 280 (FIG. 20). Since both needle bars are located substantially in the upper lapping position at this instant, both the latch needles 1] of the bar I as well'as the latch needles 12 of the bar 11 are shown in section.

Since the curve 8 of the oscillatory movement has its turning point at a 100, the guide bars at this instant, as for the aforedescribed heretofore known method in the stage thereof shown in FIG. 1b, are symmetric to the vertical axis 5 of the machine. FIG. 2d shows this position diagrammatically in side elevational view with the eye needles 21 to 25 of the corresponding guide bars. This position of the eye needles 21 to 25 is also shown in the horizontal sectional view of FIG. 2b.

From the mid-position of FIG. 2d, the guide bars initially swing rearward i.e., toward the right-hand side as viewed in FIG. 2d, and at or equal to about 130 attain the position shown in FIG. 2e wherein the latch needles 11 drop while the latch needles 12 persist in the lapping position. Meanwhile, in FIG. 2b the eye needle 21 has reached the point a. Then, the underlapping back-fill begins for the eye needle 21 so that the latter, in accordance with the dot-dash line, within the knitting needle bars, at the end of the underlapping displacement, has

attained the position 21a for an angular position of 220 of the main machine shaft. FIG. 2f shows the position at a 190. It is apparent that the underlapping thread of the eye needle 21 is placed at the bar of the latch needles 12. The penetration of the eye needle 21 into the bar of the latch needles 11 is effected at arotary angle a 250 according to FIG. 23. It is also apparent that the eye needle 21 only carries out an under lapping to the latch needles 11, while the remaining eye needles 22 to 25 can complete an overlapping to the latch needles 12. The spacing between the eye needles 21 and 22 as well as between the eye needles 24 and 25 is so large, accordingly, that the latch needles 11 or 12 can penetrate into the intermediate spaces.

As is shown in FIG. 2b, only the eye needles 23 and 24, in the illustrated embodiment of the invention, complete an overlap. The eye needles 22 and 25 swing through without any backfilling and reach the positions 22a and 25a, respectively, whereas the eye needles 23 and 24 on the needle bar 11 complete an overlapping backfill which, at about a rotary angle of 160 of the main machine shaft, begins at point b of FIG. 2b and, after an additional rotation of the main shaft through an angle of 60, is terminated at about a 220 i.e., at the same instant as the underlapping backfill of the eye needles 21 ends. The needles 23 and 24 have then attained the positions 23a and 24a, respectively.

The guide bars again reach the position of FIG. 2d at a rotary angle of about 280 of the main machine shaft according to FIG. 2b, however, with the difference that the guide bar packet swings forward i.e., to the lefthand side as viewed in FIG. 2b. After'a further rotation of the main shaft through an angle of 30, the position of FIG. 2i at 310 is attained, which is a mirror image of FIG. 2e, and in which the underlapping back filling or offset of the eye needles 25 to the knitting needles 12 of the rear needle bar begins. After 30 rotation of the main shaft later, at 340, the overlapping displace ment of the needles 22 and 23 begins. Both the overlapping and underlapping displacements are completed at 400. These offset movements of the eye needles 21 to 25 are shown in FIG. 2c as the paths from 21b to 21c, from 22b to 220, and so forth. To facilitate the completion of the underlapping as well as the penetration of the knitting needles into the guide bar needles individual guide bar needles are twisted through an angle of substantially as shown in the two views of FIGS. 3a and 3b. This twisting or crossing is of considerable importance when the number of guide bars is increased. Moreover, it can be seen in FIGS. 2b and 2c that with this embodiment, due to the selected needle distribution, the knitting needle bars are cast respectively with one needle position filled and two empty, so that the eye needles can even swing broadside through the large passages consequently provided.

FIG. 4' shows diagrammatically the basic structure of a double needle-bar warp knitting machine for carrying out the method of the invention in the instant application. Shown therein is the main drive shaft 41 of the machine, for which a suspended shaft 1 43 is driven through the intermediary of an eccentric 42 at a trans mission ratio of 1:1 to effect the oscillatory movement of the guide bars 44. It is to be noted at this juncture also that the guide bar needles 21, 22 and 24, 25 are twisted through an angle of 90 whereas the guide bar needles 23 which form stitches on both bars remain untwisted. Furthermore, FIG. 4 clearly shows the knitting needles 11 and 12 as well as a fabric or web drawing-off system including a fabric beam 45.

As mentioned hereinbefore, the invention of this application has been illustrated in FIGS. 2a to 2i in a specialembodiment thereof which can, of course, be varied in many different directions within the scope of the invention. Among others, it is possible, instead of a purely sinusoidal oscillatory movement 8 of the guide bars, to introduce a slight delay or pause into the oscillation. Furthermore, it is not difficult to realize from the figures of the drawing, that not only the eye needles 23 on both needle bars can form stitches, but also the eye needles 22 and 24 can form stitches on both needle bars with a suitable control. It should also be noted that the invention of the instant application can also be employed with particular advantage in warp knitting machines having a greater number of guide bars than that shown in the embodiment illustrated in the drawing. We claim: I

1. In a method of operating a double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, at least one of theguide bars forming stitches on both of the needle bars, the steps of displacing the guide bars in a single oscillating movement into operative relationships with both the needle bars for one rotation of the main drive shaft, and moving said needle bars to accommodate said displacing motions of said guide bars.

2. Method according to claim 1 wherein the oscillating movement of the guid bars is sinusoidal, thereby providing maximum machine operating speed.

3. Method according to claim 1 including displacing the knitting needles of both needle bars between a lapping position thereof and a knocking-over position thereof, the knitting needles pausing in the knockingover position for a shorter period of time than in the lapping position.

4. Method according to claim 3 wherein the pause in the knocking-over position of the knitting needles corresponds at most to the period of rotation of the main drive shaft through a rotary angle of 90.

5. Method according to claim 3 wherein the pause in the lapping position of the knitting needles corresponds to the period of rotation of the main drive shaft through a rotary angle of substantially 180.

6. Method according to claim 1, which comprises forming an overlap on the knitting needles of one needle bar by means of one of the guide bars that is associated therewith, and simultaneously forming an underlap on the knitting needles of the other needle bar by means of another of the guide bars that is associated with the other needle bar.

7. Method according to claim 6 which comprises back filling with the needles of the guide bars forming the underlap within the knitting needle bars.

8. Method according to claim 3 which comprises drawing-off the knitted cloth at least mainly in the knocking-over position of the knitting needles.

9. Double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, comprising means for controlling movement of the guide bars so that at least one guide bar forms stitches on both needle bars, and transmission means driven by the main machine drive shaft to effect oscillatory movement of the one guide bar, said transmission means having a transmission ratio of 1:1 effecting displacing the guide bars in a single oscillating movement over the needle bars for one rotation of the drive shaft, wherein the guide bar carries lapping needles spaced from one another a distance large enough to permit the needles of the guide bars to penetrate into the space therebetween to produce an overlap on the knitting needles of one needle bar and, simultaneously, an underlap on the knitting needles of the other needle bar.

10. Warp knitting machine according to claim 9 wherein said transmission means comprises an eccentric drivingly connected to the main drive shaft of the machine to effect sinusoidal oscillating movement of the guide bars.

11. Warp knitting machine according to claim 9 wherein the guide bars carry a plurality of lapping needles, and wherein at least one of the lapping needles of each guide bar is disposed cross-wise at an angle of substantially to the other lapping needles of the respective guide bar.

12. Warp knitting machine according to claim 9 wherein the needles of both needle bars are offset, re-

spectively, from one another. 

1. In a method of operating a double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, at least one of the guide bars forming stitches on both of the needle bars, the steps of displacing the guide bars in a single oscillating movement into operative relationships with both the needle bars for one rotation of the main drive shaft, and moving said needle bars to accommodate said displacing motions of said guide bars.
 2. Method according to claim 1 wherein the oscillating movement of the guid bars is sinusoidal, thereby providing maximum machine operating speed.
 3. Method according to claim 1 including displacing the knitting needles of both needle bars between a lapping position thereof and a knocking-over position thereof, the knitting needles pausing in the knocking-over position for a shorter period of time than in the lapping position.
 4. Method according to claim 3 wherein the pause in the knocking-over position of the knitting needles corresponds at most to the period of rotation of the main drive shaft through a rotary angle of 90*.
 5. Method according to claim 3 wherein the pause in the lApping position of the knitting needles corresponds to the period of rotation of the main drive shaft through a rotary angle of substantially 180*.
 6. Method according to claim 1, which comprises forming an overlap on the knitting needles of one needle bar by means of one of the guide bars that is associated therewith, and simultaneously forming an underlap on the knitting needles of the other needle bar by means of another of the guide bars that is associated with the other needle bar.
 7. Method according to claim 6 which comprises back filling with the needles of the guide bars forming the underlap within the knitting needle bars.
 8. Method according to claim 3 which comprises drawing-off the knitted cloth at least mainly in the knocking-over position of the knitting needles.
 9. Double needle-bar warp knitting machine having a main drive shaft and a plurality of guide bars operatively connected thereto, comprising means for controlling movement of the guide bars so that at least one guide bar forms stitches on both needle bars, and transmission means driven by the main machine drive shaft to effect oscillatory movement of the one guide bar, said transmission means having a transmission ratio of 1:1 effecting displacing the guide bars in a single oscillating movement over the needle bars for one rotation of the drive shaft, wherein the guide bar carries lapping needles spaced from one another a distance large enough to permit the needles of the guide bars to penetrate into the space therebetween to produce an overlap on the knitting needles of one needle bar and, simultaneously, an underlap on the knitting needles of the other needle bar.
 10. Warp knitting machine according to claim 9 wherein said transmission means comprises an eccentric drivingly connected to the main drive shaft of the machine to effect sinusoidal oscillating movement of the guide bars.
 11. Warp knitting machine according to claim 9 wherein the guide bars carry a plurality of lapping needles, and wherein at least one of the lapping needles of each guide bar is disposed cross-wise at an angle of substantially 90* to the other lapping needles of the respective guide bar.
 12. Warp knitting machine according to claim 9 wherein the needles of both needle bars are offset, respectively, from one another. 